Print Sorted Array Index - C++

#include <iostream>
#include <vector>
#include <unordered_map>
#include <algorithm>
using namespace std;

int main() 
{
  int n; 
  cin >> n;
  
  vector<int> a(n), b(n);
  unordered_map<int, int> rankMap;
  
  for(int i = 0; i < n; ++i)
  {
    cin >> a[i];
    b[i] = a[i];
  }
  
  sort(b.begin(), b.end());
  
  for(int i = 0; i < n; ++i)
  {
    rankMap[b[i]] = i+1;
  }
  
  for(int i = 0; i < n; ++i)
  {
    cout << rankMap[a[i]] << " ";
  }
  
  return 0;
}